Do you think it'd be one game or both games?
The first game was originally planned to be chapters 1-6, I think.
If it's only one game there could be a problem with branding the 3rd game as it'd go Shenmue HD => Shenmue 3.
One possible solution could be to name it "Shenmue - Chapters 1-6" and then name Shenmue 3 "Shenmue - Chapters 7-??"
Would you like two games or to experience as one as originally planned?